1. Field of the Invention
The invention relates in general to elevator systems, and more specifically to new and improved apparatus and methods for generating a landing and leveling speed pattern for elevator systems.
2. Description of the Prior Art
A speed pattern for an elevator car is usually time based until the car reaches a distance from the target floor at which it must start the slowdown phase of the run. At this point, a distance based slowdown pattern is usually substituted for the time based pattern. When the distance-to-go value from the elevator car to the target floor is based upon updating a counter with pulse wheel generated distance pulses, or when it is determined by any other method in which the car position is not absolute, it is common to switch to a hatch transducer arrangement which provides an analog landing speed pattern which starts, for example, when the elevator car reaches a point 10 inches (25.4 cm) from floor level and continues until the car has stopped level with the floor. The hatch transducer includes a pair of car mounted transformers, associated circutry, and a metallic hour glass shaped landing vane at each floor. The landing and leveling is thus under the direction of a speed pattern based on absolute car position. While excellent landings are made using the hatch transducer, it does require substantial time to adjust the landing vane at each floor, in order to produce good landings, and even then the landing pattern may vary slightly from floor to floor. Also, being analog, the circuitry is subject to drift and it requires periodic adjustment.